I have the RRA 20" Standard flattop. I thought the EOP (Although unique) would put my optics too high off of bore. I use RRA's 1 piece scope mount, which rocks.
As soon as the photoserver returns to operation, I'll post some pics.
IM me your email, and I'll send you photos.
BTW, I had to wait almost 4 months for RRA to build my upper. DEFINITELY worth the wait!!!

I've got a 16" RRA varmint upper w/o the EOP. It works fine with medium height scope rings...I think the EOP would make stuff too high IMHO by the time add the height of even low rings. As far as which kind of rings, it really depends on $$$. I can barely afford the rifles without spending $150 on rings, so I'm gonna defer to other folks on that one..but my 20" Armalite upper shoots consistent sub moa groups with no name rings and a Simmons 6x18 scope if that's any help.
The RRA varmint is a fairly hefty upper...adding another 4" of barrel would probably be noticeably heavier. I decided on 16" figuring I'm never gonna be shooting this thing past a couple of hundred yards. If you're looking to go 400 yards, you're almost getting past the point of what a lot of folks consider the end of the .223's effectiveness...unless you're thinking of the 24" barrel...which will add even more weight.
Personally, I think I'd stick with the 18"...and get a .22-250 for those 400 yard shots [:D]
Damn...I was gonna post a pic...but all my pics are now GONE from my Hunting-Pictures.com account...not good hehehe.

I would go with the raised built in mount. I got the low version and could not cycle the action of the charging handle with my scope. I ended up getting a set of raised rings which are about the same height as the fixed ones you have shown. 20" will be fine with the right optics. I have been told to get upper end optics if you want anything acurate to 400 yards. I would personally go with the highest magnification you can find in the upper end scopes. www.Model1sales.com also have some match grade barrels made my E.R. shaw that are real good & prices a bit better.. IMHO i would say E.R. shaw barrels are a bit better than wilson barrels (RRA supplier). But they both will knock em down..... Check out their options. But definitely stay with the RRA two stage trigger....
Prosise

Originally Posted By Prosise:
and could not cycle the action of the charging handle with my scope.
Prosise

View Quote

As soon as I find someone to host pics, I'll show you guys how it is done!!!
I added a side charging handle latch. Now, I can rack it with just my left hand, while not bumping the scope or having to contort my hand to get it under the scope.
Well worth the $.

Mugzilla,
Thanks for the pictures, looks just like what I want. Although, I probably will go for the 16 or 18" version. 400 yards is probably being a little unreasonable for .223
Fenian,
Yeah, 400's probably too far. 16" or 18" will do.
Prosise,
I think the standard A4 will work, especially with the the mount that Mugzilla'a using.
Here are some pictures that Mugzilla sent me. Nice looking setup, definitely need a shorter bipod(which he is planning on doing). I've got two of the Harris LM's that i think are ideal.
Steve
[img]http://mediaservice.photoisland.com/auction/May/2003576028239300014573.jpg[/img]
[img]http://mediaservice.photoisland.com/auction/May/2003571315105576674546.jpg[/img]

11-13Lbs???
I still want it, guess I'll have to start working out a little more...
Here is the side charging handle you mentioned.
Steve
[img]http://mediaservice.photoisland.com/auction/May/2003576168946703760206.jpg[/img]

OFr all those tuning in, that is a Bushmaster buttstock, DPMS PSG-1 style grip, and a bushnell trophy 6-18x40.
The bipod is for sale/trade, if anyone is interested. I need a shorter one with extending legs...
mjp